Hip Joint Function: Transmits weight from the body to the LE.

Blood Supply to femoral head:

• Medial circumflex: supplies blood to the neck of the femur/hip.

• Lateral circumflex: supplies blood to the muscles of the hip.

• Branch of obturator artery: ligamentum teres (transmits blood from the artery to the head of the femur).

• If AVN occurs it means the blood supply to the bone is lost.

Nerve supply to Hip Joint:

• Femoral nerve:

  • Sensory to the anterior thigh.

  • all QUADS + pectineus.

  • seen in the femoral triangle.

• Obturator nerve:

  • Adductors.

  • Obturator externus.

  • Sensory to the skin of the medial thigh.

• Superior gluteal nerve:

  • Glute med and min.

• Nerve to quadratus femoris:

  • Quadratus femoris.

Joint Capsule: Encases the head & neck of the femur.

• Partial vacuum within the joint space.

• The ligamentum teres attaches to the labrum, acetabular rim, and medial greater trochanter at the intertrochanteric line anterior and crest posteriorly.

Ligaments of the hip joint:

• All ligaments are taut in extension and relaxed in flexion.

• ER: superior iliofemoral and pubofemoral are taut.

• IR: Ischiofemoral is taut.

• ABduction: tightens the pubofemoral and ischiofemoral.

• ADduction: tightens the superior iliofemoral.

• Iliofemoral (Y ligament): Reinforces hip anteriorly.

  • Strongest ligament.

  • Prevents HYPEREXTENSION during standing.

  • Crosses the joint anteriorly from the AIIS-intertrochanteric line.

• Pubofemoral ligament: (limits ABduction).

  • Crosses hip joint on the medial inferior aspect, passes posteriorly and inferiorly from the medial acetabular rim and superior ramus of the pubis to the neck of the femur.

• Ischiofemoral: Reinforces the hip posteriorly.

  • Has anterior attachment.

  • Crosses the hip joint posteriorly attaching on the ischial portion of the acetabular rim.

  • Passes superolateral to insert on the femoral neck.

  • Most commonly injured

Angle of Inclination: Femoral Shaft and Neck.

• Stress occurs at the hip joint, muscle imbalance, leg length discrepancies, and knee implications.

• Normal angle = 125-130 degrees.

• In childhood the angle is greater: 150 degrees.

• Angle of inclination refers to a line going though the head, neck, and shaft.

Decreased Angle of Inclination: Coxa Vara

• The angle is reduced to 90 degrees, inserting more horizontally on the pelvis.

• Creates a shorter leg because there is a decrease in the distance (more moment).

• Length-tension relationship: hip abductor force is reduced because they are not as active (atrophy occurs in glutes).

• Angle can predispose the femoral neck to fractures.

• Trendelenburg gait may result from this: because of a shortened femur and weak abductors.

Increased Angle of Inclination: Coxa Valga

• The angle is increased to 140 degrees, away from midline.

• Head is directed more superiorly in the acetabulum.

• Creates a longer leg because of the increase in distance (less moment).

• Length-tension relationship: hip abductors exert greater force to counter gravity.

• Stress occurs at the medial knee.

Angle of Torsion: Relationship of head and neck to femoral condyles (in the transverse plane).

• Femur has a normal twist in relation to head and greater trochanter- when seated in the acetabulum our gait is directed forwards.

• Typically ~15 degrees.

• Hip congruence: when all is lined up in the acetabulum the foot and leg are directed forwards (normal anteversion).

Retroversion: less than 15 degrees.

• Decreased torsion causing a toe-out gait (5 degrees).

• Femoral neck is angled back so when the femoral head is lined in the acetabulum ER occurs.

Anteversion: greater than 15 degrees.

• Increased torsion causing a toe-in gait (35 degrees).

• Femoral neck is directed more forward so when the femoral head is lined in the acetabulum IR occurs “pigeon toed”.

• Congenital dislocation because kid’s typical angle is increased (W-sitting).

Angle of Inclination: At the knee.

Genu Valga:

• Increased angle of the distal femur and proximal tibia, the tibia moves away from midline.

• This results in lateral compressive forces at the knee (knock-knees).

Genu Varum:

• Decreased angle of the distal femur and proximal tibia, the tibia moves toward midline.

• This results in medial compressive forces at the knee (bow-legged).

Hip dislocation:

Ortolani’s Test:

• Diagnoses congenital dislocation of hip.

• Test asymmetry of thigh/inguinal folds.

• Flex the hip and knees in supine the abduct thighs.

• Resistance to abduction is an adductor spasm, clunk (+) sign.

Posterior dislocation:

• Fibrous capsule ruptures inferiorly and posteriorly when the femur is driven rearward.

• Hip dislocation is greatest when the femur is flexed and anterior force to the tibia.

• Head of the femur driven posterior out of the acetabular socket and may be traumatized, compromising blood supply to the head and neck (medial circumflex at risk).

• Potential damage to the sciatic nerve.

Anterior dislocation:

• Violent injury (hit by the car), forcing hip into extension, abduction, lateral rotation.

• Femoral head lines inferior to acetabulum.

• Frequently fractures acetabular margin.

Central dislocation:

• Violent injury to the lateral aspect of the hip, especially with hip in abduction.

• Femoral head is driven deeper into the acetabulum.

• Comminuted fracture.

Slipped Capital Femoral Epiphysis (SCFE): fracture through the growth plate which causes a slip in the neck of the femur.

• May result in coxa vara.

• Onset is gradual but can be associated with growth spurts (occurs in subadults).

Legg Calve Perthes Disease: happens during development.

• Idiopathic disease that results in blood loss to the femoral head causing flattening over time.

• Occurs in kids under the age of 10.

• May take up to 2 years to resolve, position of healing/comfort may be ABD to center the femoral head in the acetabulum.

• Limited in flexion, abduction, and IR.

• Lack of blood flow and bone dies (AVN) weakened bones may break and reheal.

Avascular Necrosis (AVN): pathologic process that results from interruption of blood supply to the bone.

• May present as a lack of hip extension and ER.

• Sign of comfort would be open pack position: slight flexion, ABD, and ER to minimize the pressure on the femoral head.

Femoral Acetabular Impingement (FAI):

• Cam: enlarged femoral head/neck.

• Pincer: enlarged acetabular rim.

• Pain in groin, butt, and medial knee.

• Test using IR and ADD (decrease in ROM).

Snapping Hip Syndrome: 3 types

• Iliopsoas snaps over the iliopectineal eminence or the femoral head.

• IT band snaps over the greater trochanter of the femur.

• Intrarticular: snapping labral tear.